Ensuring preparedness against increasing threats from North Korea should be a top priority for the next US administration, top military officials said Monday.

"North Korea plays heavily in my mind because the situation is so unpredictable and the pace seems to be increasing there. There are quite a few soldiers sitting right there, ready in case something happens," Army Secretary Eric Fanning said in response to a question about what to prioritize to his successor during a security seminar.

"So, making sure that we are prepared for this increasing threat as our current capabilities increase is a very important part of the calculus," he said during the seminar involving the secretaries of the Army, the Navy and the Air Force.

Navy Secretary Ray Mabus also called for solid preparedness for all threats.

"It's not just North Korea. I think any incoming administration has got to be ready from day one for any other threats that are out there, and that is part of our job to pass to our successors is the readiness that's there," he said.

Mabus said it's part of efforts to ensure readiness that the US has forward deployed its forces.

"Our soldiers are there on ground in South Korea ... We've got a carrier. In Japan we're adding destroyers to that effort and ballistic missile destroyers. They're there, they're forward so if there is a crisis, you don't have to wait," he said.

"Doesn't matter what those forces are, you've got to have them forward, you've got to have them ready and you've got to be ready, in Marines' terms, to fight tonight. I think that not just North Korea, but that has to be what we pass on to our successors," he said.

Air Force Secretary Deborah Lee James said the next administration should immediately begin a strategic review of threats. Conducting a review of the status of nuclear weapons should also be a priority, she said. (Yonhap)